Project "Honolulu" is the culmination of significant customer feedback, which has directly shaped product direction and investments. With support for both hybrid and traditional disconnected server environments, Project "Honolulu" provides a quick and easy solution for common IT admin tasks with a lightweight deployment.

I've never managed any servers, so it's difficult for me to gauge how useful of popular tools like these are. What is the usual way people manage their servers?

manage the rest of the servers from one of your lesser used domain controllers.

Why would you ever do that?.. That's horrible practice. Usually, you would have a dedicated admin server with terminal services role and licenses for many concurrent admins, plus all the needed administration tools installed on it.
Domain controllers, like all the other servers, need to be left alone to do their role. If you're using some server for admin work that is not dedicated for admin work, you're doing it wrong.